Which common sheep disease causes degeneration of muscles in lambs?

• A. Footrot
• B. Scrapie
• C. White muscle disease
• D. Enterotoxemia

Answer: (C)

White muscle disease is a nutritional myopathy caused by selenium deficiency (often with low vitamin E) that leads to degeneration of skeletal and sometimes cardiac muscles in lambs. Selenium is part of glutathione peroxidase, which protects muscle cells from oxidative damage; without it, muscle fibers deteriorate, especially in newborn lambs. Clinically, this shows as weakness, stiff gait, difficulty standing, and can progress to recumbency or sudden death if the heart is affected. Prevention relies on adequate selenium and vitamin E for pregnant ewes and for lambs through diet or supplements. The other conditions listed affect different systems—footrot harms the hooves, scrapie is a neurodegenerative disease, and enterotoxemia targets the gut—so they don’t cause the muscle degeneration seen with white muscle disease.